A fellow passenger calling from the San Francisco International Airport tarmac after the Boeing 767 landed said a woman passenger had "a complete meltdown freakout" over the Pacific Ocean.
The witness, Elizabeth Oglesby, told The Associated Press that the woman hit a pilot in the chest after he left the cockpit to check on her.
"She appeared to be out of her mind. Upset. Belligerent," Oglesby said. "He threatened to handcuff her if she didn't calm down. At that point she hit him in the chest."
A U.S. Transportation Security Administration spokeswoman did not have the passenger's name, but said she was taken to the hospital.
Delta Flight 511 originated in Cincinnati and was supposed to fly nonstop to Honolulu.